Jamb liners, particularly those used for mounting take-out windows, include slots for exposing shoes at ends of window sash counterbalances. The shoes track within channels formed in the liners and are connected to the window sash by pins that project through the slots.
As a matter of manufacturing convenience, the slots are formed along the full height of the jamb liners, even though the shoes are required to track along only part of the jamb height. The unused part of the slots, particularly apparent in lower sash runs of double-hung windows, present an unsightly view when the lower sash is closed. The slot opening in the jamb liner also permits contaminants to enter the shoe channel and adjacent spring channels, which possibly harm or obstruct operation of the window balance system.
There are slot covers that have been used in the past to close these slots, but it has been necessary to insert these covers into place before the jamb liners are installed. The known cover has a generally H-shaped configuration formed by two interconnected flanges that engage portions of the jamb liner adjacent to the slot, and this prevents the slot cover from being easily removed or replaced once the window has been assembled.